• Journal of Embryo Transfer
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• v.4 no.1
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• pp.41-45
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• 1989

Total thirty of flushing were attempted on day 4 to 15 of estrus cycle with S heifers and 9 cows by nonsurgical method. The flushed or recovered rate among flushings was 86.7% (26/30) or 88.5% (23/26), respectively. There was no difference in the recovered rate between heifers (85.7%,6/7) and cows (89.5%, 17119). The embryo was recovered on day 4 to 15 of estrus cycle from the donors in natural heat without any technical difficulties.The I2FG Foley catheter used for pubertal heifers had sometimes plug in it with uterine mucus during flushing of uterine horn. But the problem could be overcomed by pumping the catherter with fluthing solution or by changing the catheter. Three normal embryos were recovered from 3 pubertal (10-11 month old) heifers. The rate of normal and abnormal eggs was 60.9% (14123) and 39.1% (9/23), respectively. The abnormal eggs were on degenerating except one unfertilized egg and were mostly recovered from heifers or cows flushed consecutively during the estrus cycle. The developmental states of normal embryos were l6-cells on day 5, 32-cells on day 6, compacted-morula on day 7, early-to expanded-blastocyst on day 8-to 9, and hatching-to hatched-blastocyst on day 10 to 11 of estrus cycle. The stage of embryos on day 8 to 10 showed varities among donors. On day 8 to 9 of estrus cycle hatching-blas tocyst was recovered from some donors.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.384-388
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• 2003

To establish the method of estrus induction using the injection of PGF$_2$$\alpha$ㆍ the 60 dairy cows treated by PGF$_2$$\alpha$ㆍ at 6, 8, 10, 12, 14, and 16 day of estrous cycle, recpectively. The plasma progesterone concentrations at day of injection of PGF$_2$$\alpha$ㆍ were $1.5\pm$1.3 (mean$\pm$SD) ng/ml at 6 days of estrous cycle, 3.7$\pm$1.4 ng/ml at 8 days, 6.5$\pm$1.8 ng/ml at 10 days, 7.9$\pm$2.0 ng/ml at 12 days, 6.5$\pm$2.5 ng/ml at 14 days, and 2.5$\pm$1.2 ng/m] at 16 days, respectively. The percentages of induction of estrus after PGF$_2$$\alpha$ㆍ treatment were 52.8% at 3th day after treatment, 21.7% at 4th day, 8.3% within 2th day, and ] 7.2% after 5th day, respectively. The percentages of cows conceived at first service after induction of estrus were 73.3% on 16 days of estrous cycle at treatment, 66.7% on 10 and 14 days, 63.3% on 8 and 12 days, and 53.3% on 6 day, respectively. The percentages of cows conceived on first service were 70.5% at 3th day after induction, 66.7% at 4th day and 65% at 5th day, respectively. These results suggest that the PGF$_2$$\alpha$ㆍ treatment at regressing stage of corpus luteum showed high induction of estrus and pregnancy rate, and there were high induction of estrus and pregnancy rate at 3th and 4th day after PGF$_2$$\alpha$ㆍ treatment.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.160-168
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• 2017

Tscherskia triton is widely distributed in Northern China, Korea, and the adjacent areas of Russia. Except its distribution, reproduction, and growth development related to life history, reproductive cycle and reproductive organs of T. triton are rarely studied in Korea. The purpose of this study was characterized the estrous cycle of T. triton captured in Jeju Island in order to provide information to a better information of captive breeding of the species when long-day (16L : 8D) and short-day (8L : 16D) photoperiod. Then, histological study of the ovaries and uterus with five females in each photoperiod was performed. The duration of the estrus cycle was 4~5 days and it showed regular cycle pattern. Results of the vaginal cytology examination showed four characteristic phase of the estrous cycle in long-day photoperiod (16L : 8D): proestrus, estrus, metestrus and diestrus. However, in short-day photoperiod, the diestrus phage of the estrus cycle was maintained from the $6^{th}$ to $12^{th}$ day. In the long-day photoperiod, females had many Graafian follicles and corpus luteums in large ovaries, and developed uterine glands in the thick endometrium. But they had some primary, secondary and tertiary follicles, and undeveloped uterine glands in the thin endometrium during short-day photoperiod. These results were identified difference of the estrus cycle and histological characteristics of reproductive tracts according to the photoperiod. These results are very important clues to the reproductive biology of T. triton, and it will be widely used as date for maintaining biodiversity.

• Journal of Embryo Transfer
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• v.29 no.2
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• pp.183-188
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• 2014

A study was carried out on 16 indigenous ewes in Bangladesh in order to assess the reproductive physiology, the pattern of vaginal cell exfoliation and progesterone profiles during the estrous cycle period. The mean estrous cycle length and duration of estrus were $15.8{\pm}0.12$ days and $31.1{\pm}0.57$ h respectively. The exfoliated epithelial cells were categorized into parabasal, intermediate, superficial and keratinized and their relative occurrences. The percentages of parabasal, intermediate and superficial cell type during proestrus were similar. The percentage of superficial cell type during estrus was 61.7%, which was significantly (p<0.01) differ from other types of cells and stages of estrus cycle. Metoestrus was predominant with neutrophils in addition with other cell types. Dioestrus was dominated by neutrophils. On days 0 to 5 of the cycle the progesterone concentration was 0.09 to $1.6{\pm}0.07ng/ml$. The length of diestrus was 5~10 days with a range of mean progesterone level of $1.6{\pm}0.07$ to $2.8{\pm}0.11ng/ml$. Progesterone levels increased significantly (p<0.01) after Day 5 and maximum level was $2.8{\pm}0.11ng/ml$ observed on Day 10 of the estrous cycle. Thereafter it dropped rapidly to basal level of $0.11{\pm}0.04ng/ml$ on Day 0 (p<0.01). These results indicate that the pattern of exfoliation of vaginal cells along with progesterone concentration could be used to determine the reproductive stages of indigenous ewe.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.62-69
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• 1985

The present study was carried out to determine sex hormone levels in serum throughout estrous cycle in Korean native goats. LH, FSH, prolactin, estradiol-$17{\beta}$ and progesterone in serum analyzed every 2 days from the estrus (day 0) to the 20th day of estrous cycle by the radioimmunoassay. The concentration of serum LH was high level with 3.27 mIU/ml on the day of estrus, then decreased rapidly to l.05~1.73 mIU/ml from the day 2 of estrous cycle to the day 18. A similar tendency was observed in the prolactin concentration, however the ranges of variation were not so marked as those of LH concentration. FSH concentrations determined were below 1.25 mIU/ml in all observation time. The concentration of serum estradiol-$17{\beta}$ was the highest, 23.62 pg/ml on the day of estrus, but the levels of 4.56~9.75 pg/ml were maintained during the other days of estrous cycle. Progesterone concentrations were the lowest, 0.45 ng/ml on the day of estrus and thereafter increased gradually to 8.85 ng/ml on the day 14 of estrous cycle, then decreased again. Serum LH concentrations before and after estrus maintained high levels during the 12 hours, i. e., 6 hours before and 6 hours after estrus. The concentrations of FSH were below 1.25 mIU/ml during the observation period. Prolactin concentrations were observed high levels during 24 hours, i.e., 12 hours before and 12 hours after estrus. Estradiol-$17{\beta}$ concentrations before and after estrus maintained high levels during the 24 hours, i.e., 12 hours before and 12 hours after estrus. The tendency of changes in progesterone concentrations were contrary to that of estradiol-$17{\beta}$.

• Journal of Embryo Transfer
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• v.25 no.1
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• pp.67-75
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• 2010

To investigate the change of vaginal epithelial cell in estrus-induced Shih-tzu bitch, estrus was induced by PMSG (50 IU/kg, for 10 days) and hCG (1,000 IU, on Day 10) in 12 anestrus Shih-tzu bitches. Day-changes of vaginal epithelial cells during the whole period of hormone treatment were investigated in each experimental bitches. The first day of vulvar bleeding and the first day of male acceptant was on $6.72{\pm}1.38$ days ($Mean{\pm}S.D.$), and $10.44{\pm}1.63$ days after the first PMSG treatment. The duration of proestrus and estrus was $4.36{\pm}1.20$ days, and $7.58{\pm}1.43$ days. Characteristic features of vaginal cytology during the estrous cycle were the high proportion of large intermediate cell, superficial cell, anuclear cell and erythrocyte in proestrus, superficial cell and anuclear cell in estrus, and parabasal cell, small and large intermediate cell, and leukocyte in diestrus, respectively. When it was timed from the first day of PMSG administration (Day 0), the cornification index (CI) was the high proportion in proestrus and estrus. The CI peak was maintained above 80% between Day 11~14 (4 days) and CI showed a peak at Day 12. These results indicated that the 12 Shih-tzu bitches showed positive estrus induction by vaginal smear test and observation of clinical estrus sign.

• Korean Journal of Animal Reproduction
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• v.14 no.3
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• pp.175-182
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• 1990

Behavioural estrus and short estrous cycles were observed and serum concentrations of estradiol-17$\beta$(E2) before and after of estrous were measured following superovulation treatments in 30 pluriparous Korean native goats. The goats were divided into 2 groups. Fifteen goats were injected IM with 1,000IU PMSG on Day 12 of the estrous cycle followed by 10mg PGF2$\alpha$ 48h later(P4＋PMSG), and the other 15 goats were injected IM with 10mg progesterone(P4)in oil once daily for 10d beginning at any days of estrous cycle followed by 1,000IU PMSG and 10mg PGF2$\alpha$ at the 8th day of progesterone treatment(P4＋PMSG group). After injection of PGF2$\alpha$, onset of standing estrus occurred in 12 of 15 goats(80.0%) at 50.0$\pm$7.7h and in 11 of 15 goats(73.3%) at 135.6$\pm$10.1h in PMSG and group and P4＋PMSG group, respectively. The mean interval from PGF2$\alpha$ injection to first estrus was significantly(P<0.01) earlier in PMSG group than in P4＋PMSG group. This result indicate that the delayed infusion of P4 in P4＋PMSG group caused the later exhibition of their estrous behaviors. However, duration fo frist estrus(31.5$\pm$2.6h vs 26.2$\pm$2.3h), length of estrous cycle(14.1$\pm$3.3d vs 16.6$\pm$3.8d) and percentage of short estrous cycle(50.0% vs 45.5%) were not different between PMSG and P4＋PMSG group. The mean concentration of serum E2 in 4 goats showing normal estrous cycle in P4＋PMSG group(PP-NEC) was higher than in 6 goats showing normal(P-NEC) or in 6 goats showing short estrous cycle(P-SEC) in PMSG group. The peak level of serum E2 was observed at the time of onset of standing estrus in PP-NEC(67.6pg/ml), 6h earlier in P-NEC(53.1pg/ml) and 6h later in P-SEC(52.3pg/ml) than the onset of standing estrus. The profiles of serum concentration of E2 during the period of peri-estrus was similar in the goats of PMSG or P4＋PMSG and also in the goats showing the subsequent estrous cycle of normal or short length.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1205-1209
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• 2000

The present study was undertaken to investigate the effect of stimulation of follicular development with eCG on the peripheral levels of inhibin and FSH in Murrah buffaloes. Estrus was synchronized in five normally cycling females by insertion of Crestar (Intervet, Boxmeer, Holland) implants for nine days. Estradiol valerate was administered i.m. on the day of implant insertion. On the 10th day of the induced estrous cycle a single dose of 3000 IU eCG (Folligon, Intervet, Boxmeer, Holland) was given, followed by treatment with 25 mg of $PGF_2$ alpha (Lutalyse, Upjohn, Belgium) 48 h later. Blood samples were obtained during the induced estrus, on cycle day 10 (luteal phase), at the superovulatory estrus (43 h after PGF) and during the periovulatory period (64 h after PGF). Ultrasonography was done daily to monitor follicular development. Plasma concentrations of inhibin and FSH were determined by specific radioimmunoassays. Differences between $mean{\pm}SEM$ values of different phases of the cycle were compared by ANOVA. The mean number of small (2-5 mm), medium (6-9 mm) and large (>10 mm) follicles observed two days after eCG treatment and on the day of superovulatory estrus was $2.8{\pm}0.31$, $5.2{\pm}0.30$ and $1.4{\pm}0.09$ and $1.9{\pm}0.21$, $2.8{\pm}0.40$ and $5.0{\pm}0.83$, respectively. The mean number of ovulations was $3.6{\pm}0.37$ and the mean number of unovulated follicles was $6.1{\pm}0.47$. Most of the follicles >10 mm in diameter had ovulated (72%). The mean ${\pm}SEM $ of plasma inhibin concentration $(2584.15{\pm}17.92pg/ml)$ during the superovulatory estrus was significantly higher $(p{\leq}0.05)$ than during the induced estrus $(749.87{\pm}17.29pg/ml)$, the luteal phase $(1099.54{\pm}24.98pg/ml)$ and periovulatory period $(1682.71{\pm}29.88pg/ml)$, respectively. $Mean{\pm}SEM$ plasma FSH concentration during the induced estrus $(10.35{\pm}0.41ng/ml)$ was not different from that during the superovulatory estrus $(8.52{\pm}0.39ng/ml)$, but was significantly higher $(p{\leq}0.05)$ than during the luteal phase $(2.81{\pm}0.42ng/ml)$ and periovulatory period $(5.7{\pm}0.28ng/ml)$. These data indicate that treatment with eCG in buffaloes for inducing superovulation results in a significant elevation in plasma inhibin levels and a decrease in plasma FSH levels during the superovulatory estrus. Thus, we suggest that the elevated plasma inhibin coming from fully developed follicles continued for a long time which results in inhibition of FSH leading to poor ovulation in the remaining follicles, which may be the cause of suboptimal superovulatory response.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.103-110
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• 1997

The present study was carried out to investigate effects of gonadotropin, age of donor, day of estrus cycle gonadotropin injection started and season on embryo production after superovulation in dairy cattles. Embryo collection records were obtained from 177 embryo donor collections from 98 Holstein cows aged from 3 to 9 years during 4 years(1993~1996) at National Livestock Re-search Institute. Superovulation was induced by injections of 3 gonadotropins(FSH-P, FOLLTROPHIN-v* or SUPER-OV*) beginning on days 9 to 14 of the estrus cycle. Em-bryos were collected from donors using a nonsurgical technique on days 6 to 8 after insemi-nation. The results were as follows ;Number of total and freezable embryos per donor cow was affected by gonadotropin(P<0.01). The more number of total and freezable embryos wereobtained by use of FOLLTROPHIN-V (13.2, 7.4) or FSH-P (11.0, 5.7) than SUPER-OV* (5.0, 2.4). Age of donor, the day that gonadotropin was started or season didn't affect total or freezable embryos(P >0.05).

• Journal of Veterinary Clinics
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• v.19 no.4
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• pp.418-425
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• 2002

Estrus was induced in 13 anestrus Korea Jin-do bitches by intramuscular injection of pregnant mare serum gonadotropin (PMSG) in a dose of 500 lU once daily for ten consecutive days, followed by an additional single intraveneous injection of 1,000 lU of human chorionic gonadotropin (hCG) on the tenth day. Day-changes of vaginal epithelial cells during the hormone treatment were investigated in each experimental bitches and compared with the those of spontaneous estrus bitches. The first days of vulval bleeding and male acceptance after PMSG treatment were on Day 6.0$\pm$ 1.5 (mean$\pm$ SD) and Day 9.0$\pm$ 1.9, respectively. And in all of 13 bitches, vulval swelling and perineal reflex were shown. The mean durations of proestrus and estrus were 2.9$\pm$ 1.4 (mean$\pm$ SD, range ; 1-6) and 11.5: 1.7 (range ; 8-14) days, respectively, that is, duration of proestrus was significantly shorter than that of the spontneous estrous bitches but duration of estrus was longer than that of the spontaneous estrous bitches. Characteristic features of vaginal cytology during the estrous cycle were the high proportions of large intermediate cell, superficial cell, anuclear cell and erythrocyte in proestrus, superficial cell and anuclear cell in estrus and parabasal cell, small intermediate, large intermediate cell, and leukocyte in diestrus, respectively. The comification index (Cl) was significantly high proportion in proestrus and estrus, when Day 0 was timed from the first day of male acceptance, the Cl was first increased above 80% on Day 0 and maintained above 80% until Day 0 to Day 5 during 6 days and showed a peak on Day 2. Also it was maintained above 90% until Day 2 to Day 3 during 2 days. These results indicated that all 13 ekperimental bitches showed positive estrus detection by the estrus behavior and vaginal smear test after treated with PMSG and hCC. It suggested that vaginal cytology was used to estimate the optimal mating and ovulation time, in consideration of the day when the Cl was maintained above 80% in estrus-induced Korea Jin-do bitches.